You do realize that the term "shrinkage" refers to only one thing: Seinfeld-George-cold pool?
Should pry choose a different word when referring to other body parts.
HRT can and will change fat--usually by adding it, from what I've heard. It won't change bones that have already developed or cause bones to grow that have already sealed at the "bone lines" I forget the medical term for those lines. They're not joints though its something else. Maybe hem lines?.
Anyway, yeah so chances are its not the nose itself that's smaller but that the fat in surrounding areas, pry the cheeks or lips, has caused the nose to look smaller by comparison. Basically, something bigger elsewhere on your face is now drawing attention away from your nose.